The present invention relates to a practice or dummy shell or projectile for mortars and the like. The projectile includes a nose fuse, a pyrotechnic charge disposed in the shell casing of the projectile as well as a propellant charge arranged in the tail section of the projectile.
Practice or dummy shells or projectiles of the afore described type having a slight rifling are already known in the art and are, for example, described in German patent number DT-PS 1063065. The projectile body of this known projectile is transversely cut off and the tail section of the projectile is provided with a tail tube housing having guide fins, the diameter of which is substantially smaller than that of the projectile body. This tail tube housing is mounted in the main body of the projectile by being inserted in the rear portion thereof.
A pyrotechnic charge can either be disposed in the front section of the tail tube or even in front of the same in a recess of the projectile body itself. Immediately upon impact of the projectile, the pyrotechnic charge is ignited and the ensuing gas formation is forced through the long tail tube thereby expelling the rear closure plug. The marker charge which may contain smoke, flare or signal producing means becomes thereby visible.
In view of the fact that this known projectile operates as a supersonic projectile makes it very doubtful whether the long tail tube as well as the plug which is acted on by the propellant charge remain intact upon impact. In the event that the aforegoing elements of the projectile do not remain intact the visual effect of the marking charge is non-existent or ineffectual.
There is, furthermore, known another type of practice or dummy projectile which is described in German patent DT-PS 1024405. In this known practice or dummy projectile a smoke charge is mounted in the shell casing which connects with a built-in striker pin in such a way that, upon impact of the projectile, the smoke charge is ignited and the smoke is expelled through a number of openings in the shell casing. The construction of this known practice projectile having ignition and ignition transmission means is not only expensive and constructionally complex but, in the event of an ignition malfunction, has the pronouced drawback that the ignition means cannot be disassembled from the smoke charge. Consequently, the malfunctioning ignition means renders an otherwise intact smoke charge completely useless. Moreover, this known practice or dummy projectile has the additional drawback that, in the event of a sharp impact angle of the projectile one or more of the smoke omitting openings are blocked by the ground surface which considerably inhibits the visual marking effect of the projectile.
This type of projectile also represents the equivalent of an unexploded bomb having a live percussion cap and a relatively large explosive charge and has the everpresent serious danger to life and limb to anybody coming in contact with this type of projectile.